D. Sriburi, D. . Suwanjinda, and T. . Chindanurak, “The The Effects of Project-based Instruction on Initiative and Self-Directed Ability and Scientific Problem Solving Ability of the Second Year Vocational Certificate Students at Ongkharak Industrial and Community Education College, Nakhon Nayok Province”, MBU.EDU.J, vol. 10, no. 2, pp. 292–306, Dec. 2022.